Zoning & Size Limits
| Requirement | Vancouver, WA | Spokane, WA |
|---|
| Allowed Zones | Residential single-family zones | Single-family residential |
| Max Size (Detached) | 1,050 sq ft | 1,000 sq ft |
| Max Size (Attached) | 850 sq ft | 800 sq ft |
| Max Height | 35 feet | 35 feet |
| Parking Required | 1 space (optional) | 1 space per unit |
| Owner Occupancy | Not required | Not required (WA state eliminated this requirement) |
Setback Requirements
| Setback | Vancouver, WA | Spokane, WA |
|---|
| Rear Setback | 10 feet | 15 feet |
| Side Setback | 3 feet | 5 feet |
| Front Setback | 15 feet | 20 feet |
Permits & Timeline
| Detail | Vancouver, WA | Spokane, WA |
|---|
| Permit Timeline | 45-65 days | 50-75 days |
| Permit Fees | $1,900-$3,200 | $2,000-$3,500 |
| Impact Fees | $700-$1,300 | $600-$1,200 |
| Pre-Approved Plans | Available | Limited availability |
Construction Costs
| Cost | Vancouver, WA | Spokane, WA |
|---|
| Avg Build Cost | $135,000-$270,000 | $110,000-$220,000 |
| Cost Per Sq Ft | $130-$260 | $110-$220 |
| Garage Conversion | $65,000-$155,000 | $50,000-$120,000 |
| Prefab ADU | $95,000-$220,000 | $80,000-$180,000 |
Rental Income Potential
| Rental | Vancouver, WA | Spokane, WA |
|---|
| 1BR Avg Rent | $1,250-$1,700/mo | $1,000-$1,450/mo |
| 2BR Avg Rent | $1,600-$2,300/mo | $1,300-$1,900/mo |
| Short-Term Rentals | Permitted with license | Not permitted |
| Est. ROI | 7-9% annual return | 8-12% annual return |
Which City Is Better for ADUs?
Vancouver scores 7/10 while Spokane scores 6/10 on our ADU-friendliness index.
Vancouver edges ahead overall. Both cities offer viable ADU development opportunities — the best choice depends on your specific property, budget, and goals.
Finance Your ADU Project
Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders.
Some links on this page are affiliate links. We may earn a commission at no extra cost to you. Learn more
Get Quotes in Your City
Connect with pre-vetted ADU contractors and get free quotes for your project.